Few ancient states could match the scope and power of the Seleucid Empire. Founded in the late 4th century BC by Seleucus Nikator, a former officer of Alexander the Great, the Seleucid Empire at its peak included the modern states of Turkey, Syria, Lebanon, Israel, Iraq, Iran, and Afghanistan. The expanse of Seleucid rule bridged worlds, encompassing Buddhists and Jews, Greeks and Persians, walled cities and nomadic tribes. The Seleucid king might deal with an embassy from an Indian dynasty one day and a delegation of Roman senators the next. Dur: 20mins File: .mp3

Following the Civil War, Mackenzie reverted to the rank of Captain and rejoined the Corps of Engineers in New Hampshire, improving fortifications along the Atlantic coast. However, after spending the last two years in a combat command, engineering no longer held his interest. He wished to return to the field and advance his career. In early 1867, Mackenzie headed to Washington to petition General Grant to send him west. Dur: 42mins File: .mp3